import { u } from '../localizedFormat/utils'
var formattingTokens = /(\[[^[]*\])|([-:/.()\s]+)|(A|a|YYYY|YY?|MM?M?M?|Do|DD?|hh?|HH?|mm?|ss?|S{1,3}|z|ZZ?)/g
var match1 = /\d/ // 0 - 9

var match2 = /\d\d/ // 00 - 99

var match3 = /\d{3}/ // 000 - 999

var match4 = /\d{4}/ // 0000 - 9999

var match1to2 = /\d\d?/ // 0 - 99

var matchSigned = /[+-]?\d+/ // -inf - inf

var matchOffset = /[+-]\d\d:?(\d\d)?|Z/ // +00:00 -00:00 +0000 or -0000 +00 or Z

var matchWord = /\d*[^\s\d-_:/()]+/ // Word

var locale = {}

var parseTwoDigitYear = function parseTwoDigitYear(input) {
  input = +input
  return input + (input > 68 ? 1900 : 2000)
}

function offsetFromString(string) {
  if (!string) return 0
  if (string === 'Z') return 0
  var parts = string.match(/([+-]|\d\d)/g)
  var minutes = +(parts[1] * 60) + (+parts[2] || 0)
  return minutes === 0 ? 0 : parts[0] === '+' ? -minutes : minutes // eslint-disable-line no-nested-ternary
}

var addInput = function addInput(property) {
  return function (input) {
    this[property] = +input
  }
}

var zoneExpressions = [
  matchOffset,
  function (input) {
    var zone = this.zone || (this.zone = {})
    zone.offset = offsetFromString(input)
  },
]

var getLocalePart = function getLocalePart(name) {
  var part = locale[name]
  return part && (part.indexOf ? part : part.s.concat(part.f))
}

var meridiemMatch = function meridiemMatch(input, isLowerCase) {
  var isAfternoon
  var _locale = locale,
    meridiem = _locale.meridiem

  if (!meridiem) {
    isAfternoon = input === (isLowerCase ? 'pm' : 'PM')
  } else {
    for (var i = 1; i <= 24; i += 1) {
      // todo: fix input === meridiem(i, 0, isLowerCase)
      if (input.indexOf(meridiem(i, 0, isLowerCase)) > -1) {
        isAfternoon = i > 12
        break
      }
    }
  }

  return isAfternoon
}

var expressions = {
  A: [
    matchWord,
    function (input) {
      this.afternoon = meridiemMatch(input, false)
    },
  ],
  a: [
    matchWord,
    function (input) {
      this.afternoon = meridiemMatch(input, true)
    },
  ],
  S: [
    match1,
    function (input) {
      this.milliseconds = +input * 100
    },
  ],
  SS: [
    match2,
    function (input) {
      this.milliseconds = +input * 10
    },
  ],
  SSS: [
    match3,
    function (input) {
      this.milliseconds = +input
    },
  ],
  s: [match1to2, addInput('seconds')],
  ss: [match1to2, addInput('seconds')],
  m: [match1to2, addInput('minutes')],
  mm: [match1to2, addInput('minutes')],
  H: [match1to2, addInput('hours')],
  h: [match1to2, addInput('hours')],
  HH: [match1to2, addInput('hours')],
  hh: [match1to2, addInput('hours')],
  D: [match1to2, addInput('day')],
  DD: [match2, addInput('day')],
  Do: [
    matchWord,
    function (input) {
      var _locale2 = locale,
        ordinal = _locale2.ordinal

      var _input$match = input.match(/\d+/)

      this.day = _input$match[0]
      if (!ordinal) return

      for (var i = 1; i <= 31; i += 1) {
        if (ordinal(i).replace(/\[|\]/g, '') === input) {
          this.day = i
        }
      }
    },
  ],
  M: [match1to2, addInput('month')],
  MM: [match2, addInput('month')],
  MMM: [
    matchWord,
    function (input) {
      var months = getLocalePart('months')
      var monthsShort = getLocalePart('monthsShort')
      var matchIndex =
        (
          monthsShort ||
          months.map(function (_) {
            return _.slice(0, 3)
          })
        ).indexOf(input) + 1

      if (matchIndex < 1) {
        throw new Error()
      }

      this.month = matchIndex % 12 || matchIndex
    },
  ],
  MMMM: [
    matchWord,
    function (input) {
      var months = getLocalePart('months')
      var matchIndex = months.indexOf(input) + 1

      if (matchIndex < 1) {
        throw new Error()
      }

      this.month = matchIndex % 12 || matchIndex
    },
  ],
  Y: [matchSigned, addInput('year')],
  YY: [
    match2,
    function (input) {
      this.year = parseTwoDigitYear(input)
    },
  ],
  YYYY: [match4, addInput('year')],
  Z: zoneExpressions,
  ZZ: zoneExpressions,
}

function correctHours(time) {
  var afternoon = time.afternoon

  if (afternoon !== undefined) {
    var hours = time.hours

    if (afternoon) {
      if (hours < 12) {
        time.hours += 12
      }
    } else if (hours === 12) {
      time.hours = 0
    }

    delete time.afternoon
  }
}

function makeParser(format) {
  format = u(format, locale && locale.formats)
  var array = format.match(formattingTokens)
  var length = array.length

  for (var i = 0; i < length; i += 1) {
    var token = array[i]
    var parseTo = expressions[token]
    var regex = parseTo && parseTo[0]
    var parser = parseTo && parseTo[1]

    if (parser) {
      array[i] = {
        regex: regex,
        parser: parser,
      }
    } else {
      array[i] = token.replace(/^\[|\]$/g, '')
    }
  }

  return function (input) {
    var time = {}

    for (var _i = 0, start = 0; _i < length; _i += 1) {
      var _token = array[_i]

      if (typeof _token === 'string') {
        start += _token.length
      } else {
        var _regex = _token.regex,
          _parser = _token.parser
        var part = input.slice(start)

        var match = _regex.exec(part)

        var value = match[0]

        _parser.call(time, value)

        input = input.replace(value, '')
      }
    }

    correctHours(time)
    return time
  }
}

var parseFormattedInput = function parseFormattedInput(input, format, utc) {
  try {
    if (['x', 'X'].indexOf(format) > -1) return new Date((format === 'X' ? 1000 : 1) * input)
    var parser = makeParser(format)

    var _parser2 = parser(input),
      year = _parser2.year,
      month = _parser2.month,
      day = _parser2.day,
      hours = _parser2.hours,
      minutes = _parser2.minutes,
      seconds = _parser2.seconds,
      milliseconds = _parser2.milliseconds,
      zone = _parser2.zone

    var now = new Date()
    var d = day || (!year && !month ? now.getDate() : 1)
    var y = year || now.getFullYear()
    var M = 0

    if (!(year && !month)) {
      M = month > 0 ? month - 1 : now.getMonth()
    }

    var h = hours || 0
    var m = minutes || 0
    var s = seconds || 0
    var ms = milliseconds || 0

    if (zone) {
      return new Date(Date.UTC(y, M, d, h, m, s, ms + zone.offset * 60 * 1000))
    }

    if (utc) {
      return new Date(Date.UTC(y, M, d, h, m, s, ms))
    }

    return new Date(y, M, d, h, m, s, ms)
  } catch (e) {
    return new Date('') // Invalid Date
  }
}

export default (function (o, C, d) {
  d.p.customParseFormat = true

  if (o && o.parseTwoDigitYear) {
    parseTwoDigitYear = o.parseTwoDigitYear
  }

  var proto = C.prototype
  var oldParse = proto.parse

  proto.parse = function (cfg) {
    var date = cfg.date,
      utc = cfg.utc,
      args = cfg.args
    this.$u = utc
    var format = args[1]

    if (typeof format === 'string') {
      var isStrictWithoutLocale = args[2] === true
      var isStrictWithLocale = args[3] === true
      var isStrict = isStrictWithoutLocale || isStrictWithLocale
      var pl = args[2]

      if (isStrictWithLocale) {
        pl = args[2]
      }

      locale = this.$locale()

      if (!isStrictWithoutLocale && pl) {
        locale = d.Ls[pl]
      }

      this.$d = parseFormattedInput(date, format, utc)
      this.init()
      if (pl && pl !== true) this.$L = this.locale(pl).$L // use != to treat
      // input number 1410715640579 and format string '1410715640579' equal
      // eslint-disable-next-line eqeqeq

      if (isStrict && date != this.format(format)) {
        this.$d = new Date('')
      } // reset global locale to make parallel unit test

      locale = {}
    } else if (format instanceof Array) {
      var len = format.length

      for (var i = 1; i <= len; i += 1) {
        args[1] = format[i - 1]
        var result = d.apply(this, args)

        if (result.isValid()) {
          this.$d = result.$d
          this.$L = result.$L
          this.init()
          break
        }

        if (i === len) this.$d = new Date('')
      }
    } else {
      oldParse.call(this, cfg)
    }
  }
})
